1. Field of the Invention
This invention relates to an electronic endoscope system in which image data, which are obtained by an electronic scope, are subjected to predetermined operations and the image data are reproduced by an outputting device.
2. Description of the Related Art
Conventionally, a medical examination using an electronic endoscope system is performed as follows. An electronic scope is inserted into the digestive organ, and image signals are obtained by an image sensor which is provided at a tip end portion of the electronic endoscope. The image signals are subjected to predetermined image processing in an image-signal processing unit to which the electronic scope is connected. The processed image signals are output to an outputting device, for example a monitor and a printer, from the image-signal processing unit. An operator manipulates the electronic rope, viewing pictures of the inside of the digestive organ which are reproduced on the monitor. Further, if necessary, still pictures of lesion portions reproduced on the monitor are output to the printer.
In the medical examination described above, the operator judges the condition of a patient by viewing the color of the inner wall of digestive organ, and judges whether a lesion has occurred or not. Accordingly, in the electronic endoscope system, it is required that the picture reproduced by the outputting device has stability regarding color.
However, the hue and brightness of the picture reproduced on the monitor and on the printing sheet depend upon the characteristics of type of monitor and printer which are connected to the image-signal processing unit. Namely, even if identical image signals are output from identical image-signal processing units, the color condition of a reproduced image differs in accordance with the type of outputting device. Namely, with respect to picture quality, differences according to the type of outputting device exist.
Accordingly, it is necessary for the operator to adjust the picture quality of the reproduced image in accordance with the characteristics of the outputting device which is connected to the image-signal processing unit. It is complicated to carry out the above-mentioned adjustment while manipulating the electric scope in the body of a patient. Namely, the adjustment of the outputting device imposes a burden on the operator. Further, if the adjustment is not carried out, the colors of images obtained by the image sensor are not able to be accurately reproduced by the outputting device, so that lesion portions may be missed by the operator.
Therefore, an object of the present invention is to provide an image-signal processing unit which can function well with various outputting devices.
In accordance with an aspect of the present invention, there is provided an electronic endoscope system, provided with an image-signal processing unit that processes image signals obtained by a scope which is connected to the image-signal processing unit attachably and detachably, and at least one outputting device that is connected to the image-signal processing unit in order to output the image signals. The electronic endoscope system comprises: an outputting device specifying tool that specifies the model of the at least one outputting device; a database storing characteristic data concerning the output characteristics of each model of outputting device; and an image-signal compensator that obtains the characteristic data from the database based on the model specified by the outputting device specifying tool, and compensates the image signals using the obtained characteristic data.
Preferably, the image-signal processing unit comprises a plurality of output terminals to which the outputting devices can be connected, and the model of the outputting devices is specified by the outputting device specifying tool with respect to each of the output terminals.
Preferably, the outputting device specifying tool comprises: a menu displayer that displays a list of models of the outputting devices; and an input tool that selects one of the models corresponding to the connected outputting devices, from the list. The said list is displayed corresponding to each of the output terminals.
Preferably, the outputting device specifying tool is a rotary switch that is provided for each of the output terminals.
Optionally, the database is stored in a storage medium that is able to be replaced.
Optionally, the image-signal processing unit is able to be connected to an information communication network, and the database is able to be maintained by a remote terminal unit which is connected to the information communication network.
For example, the outputting devices are a monitor and a printer on which the image signals are reproduced.
Preferably, the characteristic data are data concerning picture quality of an image which is reproduced by each outputting device.
For example, the characteristic data might include a compensation coefficient used for a contour correction process.
For example, the characteristic data might include a compensating value used for adjustment of the color balance of the image signals.
For example, the characteristic data might include an output level value used for gamma correction of the image signals.
For example, the characteristic data might include an output level value used for clamping the black level of the image signals.
According to the present invention, the image signals obtained by the scope are compensated in accordance with the characteristics of the outputting device which is connected to the image-signal processing unit. Therefore, even if an outputting device, whose picture quality characteristics are different from another, is connected to the image-signal processing unit, the same picture quality is guaranteed in reproduced image. Namely, it is not necessary for an operator to adjust the picture quality considering the characteristics of the connected outputting device during a medical examination, so that the burden of the operator can be reduced.
If the database is stored in the storage medium which is able to be replaced, the database can be readily updated in the image-signal processing unit of the electronic endoscope system by installing a new storage medium in which the updated database is stored. Namely, it is easy to maintain the database. Further, it is easy to maintain a secure database, by dealing with the storage medium carefully.
By connecting the image-signal processing unit to the information communication network such that the processing unit can be accessed by a remote terminal unit connected to the information communication network, it is possible to maintain the database at a place where the electronic endoscope system is not installed. Accordingly, the burden of having the personnel necessary for maintaining the database can be reduced.
Note that, the characteristic data are not limited to the compensation coefficients for the contour correction process, the value of the color balance, the output level value used in the gamma correction process, and the output level value used for clamping the black level.